Magnetic polarization of noble metals by Co nanoparticles in M-capped granular multilayers(M=Cu, Ag, and Au): An x-ray magnetic circular dichroism study

DOI: 10.1103/PhysRevB.77.184420

Authors: J. Bartolomé (CSIC-Universidad de Zaragoza) , L. M. García (CSIC-Universidad de Zaragoza) , F. Bartolomé (CSIC-Universidad de Zaragoza) , F. Luis (CSIC-Universidad de Zaragoza) , R. López-Ruiz (CSIC-Universidad de Zaragoza) , F. Petroff (Unité Mixte de Physique CNRS/Thales) , C. Deranlot (Unité Mixte de Physique CNRS/Thales) , F. Wilhelm (European Synchrotron Radiation Facility) , A. Rogalev (European Synchrotron Radiation Facility) , N. B. Brookes (European Synchrotron Radiation Facility) , L. Ruiz (Universidad Complutense de Madrid) , J. M. González-Calbet (Universidad Complutense de Madrid) , P. Bencok (European Synchrotron Radiation Facility)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 77 (18) , PAGES 184420

State: Published (Approved)
Published: May 2008

Abstract: X-ray magnetic circular dichroism spectra have been recorded at the L 2 , 3 edges of Co, Cu, Ag, and Au, and at the K edges of Co and Cu for a series of multilayer systems of partially self-assembled Co nanoparticles, both capped with alumina and with different metals (Cu, Ag, and Au). The orbital and spin moments m L and m S and their ratio m L / m S , for Co, Cu, Ag, and Au, have been determined from those measurements. The trend of increasing m L / m S for Co is the same as found for increasing the effective anisotropy K eff alumina < Cu < Ag < Au capped. It is shown that the relative increase in the surface contribution for both quantities, ( m L / m S ) surf and K S , is directly correlated. It is argued that the increase in m L with metal capping actually reflects an increase in the anisotropy of the orbital moment for the Co surface atoms. The redistribution of the number of holes in the noble metal bands by hybridization with the Co surface atom 3 d band and the polarization of the n d band by exchange interaction with the Co bands give rise to the magnetic moments derived for the three noble metals investigated.

Subject Areas: Physics, Materials

Facility: ID08, ID12 at ESRF

Added On: 19/08/2009 23:07

Discipline Tags:

Physics Magnetism Nanoscience/Nanotechnology

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